The present invention relates to a process for warm dehulling soya beans and other bean fruits and subsequently grinding them, as well as an installation for carrying out said process.
The warm dehulling of soya or other bean fruits, for example in preparing subsequent grinding, is known in general. DE-C-3544387 describes such a dehulling process, in which the fruit are heated through to the core at a certain temperature, are next subjected to a hot gas flow followed by removal of the hulls. The fruit are heated through at 50° C. to 75° C. at least partially by means of contact heat. The temperature in the gas flow is raised to 90° C.
The fruit are subjected to the contact heat in a device with hot surfaces, and to the hot gas flow on the other hand in a fixed or fluidised bed. The dehulling device can be a baffle dehuller downstream of which another fluidised bed and/or a pneumatic sifter for removing hulls can be connected. Conditioning is carried out prior to grinding.
In a known, two-step grinding procedure, a first rough grinding step employing a pair of serrated rollers, followed by a pair of rubber rollers, is followed by a reducer and this is followed by a second rough grinding step employing two pairs of serrated rollers.